Protesters who came from as far away as North Carolina and New York streamed onto the lawn of the U.S. Capitol. Most carried signs and some wore the signature pink hats from the Jan. 21 Women’s March that drew millions and helped spawn the Tax Day protest. Others carried plastic chickens and a few wore Russian-themed hats.

“My message for the president is short enough to tweet. Today across America we are taking the gloves off,” said Sen. Ron Wyden, of Oregon, the top Democrat on the Senate Finance Committee and a keynote speaker. “It’s time to knock off the tax rip offs. No more Cayman Island accounts for the insiders. No more tax breaks for shipping jobs overseas. No more special breaks for Wall Street.”

Wyden then tore into Trump’s failure to release his tax returns, highlighting legislation he’s sponsoring to require any U.S. president to release his returns annually. “President Trump has tossed this great American tradition in the trash can like a teenager trying to hide a lousy report card,” he said.

Trump is the first U.S. president in modern history not to release his returns – every president since Richard Nixon has done so. Recent polling shows 74% of Americans want to see Trump's returns.

“Knock off the secrecy, Mr. President, and publicly release your own tax returns,” Wyden said. “Disclosing tax returns is the very lowest ethical bar for a president and we are going to insist that he clear it.”

Ezra Levin, executive director of Indivisible, among the major protest groups that's formed in the past few months, said the Tax Day protest was about more than just seeing someone's 1040s.

"It’s about whether or not the president of the United States is acting in the interest of the American people or whether he’s lining his own pockets or serving another master,” Levin said. “Congress has the power to find out and they’ve used it before," including on Nixon.

A number of marchers drew parallels between Trump’s recent bomb strikes in Syria and against ISIS in Afghanistan. One protester carried a sign reading “1 Airstrike Doesn’t Erase Trump’s Lies and Russia Ties.”

“There’s a lot of dots connecting him to Putin, and I think his taxes would reveal the final dot,” said Leslie Thiel, 58, who drove from Jackson Springs, N.C. “It’s wag the dog all over again. It’s just trying to divert attention."

Rallies were held in about 150 cities, including New York, Boston, Sacramento, Calif., and San Francisco. Activists in West Palm Beach, Fla., held the “March a Lago” near the resort where Trump is spending the Easter weekend.

The protests were mostly peaceful, although In Berkeley, Calif., police arrested 13 people after fist fighting erupted at a park where about 200 people held separate rallies for and against Trump. Officers confiscated knives and makeshift weapons.

In Phoenix, about 400 protesters assembled outside the Arizona Capitol, holding signs and chanting for Trump to release his tax returns.

"Tax returns should be released, especially if Donald Trump wants to put to rest any conflicts of interest or collusion to Russia," said Gilbert resident Lauren Ghazikhanian, 31. "I feel he truly believes he is above the law."

Mesa resident Jenna McAllister, 39, who established the Facebook event for the march, said she was inspired in January after hearing Trump's comments.

"I just hope that he turns on the news today, that he listens to the radio, that he logs into Twitter, and he sees that we're here," she said.

In Burlington, Vt., several hundred people gathered, carrying a collection of colorful homemade signs ranging from the basic, hand-lettered "Reveal your taxes," to a more elaborate illustration of Trump as "The Artful Dodger."

As the marchers made their way down Church Street, Sandra Silla, who was having lunch outside with her family at Ken's Pizza, began applauding.

"We just all did our taxes," she said. "My son wrote a check for $2,500 to the IRS, so why should Donald Trump be exempt from that?"

A rally at Reno’s Wingfield Park attracted an estimated 500 people organizers said,

Paula Pennington, 67, said she attended the rally for a “simple reason.”

“It comes down to that if I have to show my taxes, he should too,” she said.

Rep. Jan Schakowsky, D-Ill., attended at a rally in Chicago. “What you saw beginning the day after the inauguration has not let up,” Schakowsky said. “We’re talking about intensity. The only question any of us get now is: What can I do?”

The idea for the march grew out of the success of a women's march on Washington that drew millions of people. Jennifer Taub, who teaches law at Vermont Law School, got the ball rolling with a tweet calling for a #showusyourtaxes protest. Taub has testified before Congress and written a book about the 2008 financial crisis.

“I’m just a law professor who sent out a tweet,” said Taub, according to the Associated Press. “I’m psyched, and I think lots of people are psyched about this. We shall see.”

“I’m all about ‘follow the money,’” Taub said. “It tells us the story about people’s priorities.”

Dominic Lyon, a 25-year-old from Upper Marlboro, Md., said the tax march shows that the activism that began the day after Trump’s inauguration continues. “Don’t stop. We’re going to continue to fight,” he said. “The founding fathers made this country the way it is so that we can have voices.”

Through the march, the Democratic Party and progressives are attempting to reroute the grassroots energy that helped derail Trump’s bid to overhaul the Affordable Care Act toward their next goal: forcing a release of his tax returns and drawing the battle lines for the upcoming debate over U.S. tax reform.

More broadly, the coalition of almost 70 progressive groups is trying to take ownership of an issue — taxes — which Republicans have championed for the past 25 years, culminating in the formation of the conservative Tea Party.

In fact, Saturday is also the eighth anniversary of hundreds of Tax Day protests that marked the emergence of the Republican-aligned Tea Party. Although the Tea Party gathered steam around opposition to Obamacare, its roots are in a backlash to former President Obama's $787 billion stimulus program.

In a Facebook page for the Tax Day marches, organizers said the events focus on government transparency, conflicts of interest and an unfair tax system. They called on supporters to "show Donald Trump that he owes us transparency."

“We’re marching on Washington, D.C., and around the country to ask Donald Trump: WHAT ARE YOU HIDING?” the organizers said on their website. “We need a president who works for all Americans, and a tax system that does, too. Release your tax returns and commit to a fair tax system for the American people.”

As a candidate, Trump said he would not release his taxes while they were being audited. After the election, he said that only the news media cared about seeing the documents. "I won," he said.

Sean Spicer said Tuesday: “We filed our financial disclosure forms the other day in a way that allows everyone to understand.”

While April 15 is normally deemed Tax Day, this year it is Tuesday, April 18, because it falls on the weekend and there a holiday in Washington, D.C., on Monday.